Japanese seems to have multiple ways of enumerating sequences. The basic one is ordinal numbers:
- Arabic (Indian) numbers like in English: 1,2,3
- classic Chinese numbers: 一、二、三 etc.
- special legal numerals: 壱、弍、参 etc.
- special version of “one”/“first” can be used初号、初版
- Latin alphabet (a, b, c, etc.).
- goujon order (AFAIK usually katakana vowels: ア、イ、ウ、エ、オ); I’ve seen this used in some dictionaries and scientific papers.
- iroha order (いろはにほへと) - not sure if actually used
Then there are some specialized ones:
- two-volume book: 上巻、下巻
- three-volume book: 上巻、中巻、下巻
- three sizes (S,M,L): 小、中、大
And something I discovered today:
- Four-item sequence (ABCD): 甲乙丙丁, apparently originating from the Chinese sexagenary year cycle
Are there any others? What are the situations you would use one over the other?